And he is now fighting for his precious young life at Belfast’s Royal Victoria Hospital, where health chiefs are using pioneering treatment in a bid to conquer the cruel disease.

Belfast Live reported Zak's plight on Friday night.

And over the weekend, thousands of pounds have been donated to help his family.

A huge crowd turned out for a fun day in his honour on Sunday. And Zak's great aunt Val Cairns and second cousin, Sharon Cairns, had their heads shaved on Monday morning to raise awareness of the Man Utd-loving boy's plight.

Zak's aunt, Cheryl Brennan, told Belfast Live the family has been inundated with support.

She said: "Over the past few days we have received amazing support with the fun day that took place in the Hanwood Centre on Sunday.

"There was £5,070 raised with an amazing turnout.

"The support from family friends and the community is so overwhelming.

"If love could cure this disease, Zakky would be the healthiest boy in the world.

"He is due to start his next part of chemotherapy this Thursday so there are still hard times ahead for Zakky and his family but with all the love and support we our receiving we can get through this."

Another aunt of Zak, Vicky Auld, told Belfast Live on Friday: “He just turned three last Tuesday.

“He had not been really sick or anything. He was just really tired.

“We thought it was just with starting nursery and the excitement of that.

“His mum and dad took him to the doctor and he was sent to hospital.

“They scanned him the next day and found a tumour in his abdomen.”

Given the size of the tumour, Zak’s parents’ Leeanne and Gareth were told doctors were unable to operate just yet.